Comment 17 for bug 1999827

Verification done with MAAS 3.1.3.

The DNS record for the MAAS server does (not) change
with MAAS 3.1.2 (3.1.3) when adding an IP address to
the network interface of the MAAS server.

On MAAS 3.1.2: DNS record changes from IP .2 (to .10)
On MAAS 3.1.3: DNS record continues at IP .2 (no .10)

MAAS 3.1.2:

 $ snap list maas
 Name Version Rev Tracking Publisher Notes
 maas 3.1.2-10926-g.5ad7060e5 30495 3.1/stable canonical✓ -

 $ maas admin version read | jq '.version, .subversion'
 "3.1.2"
 ""

 $ ip addr list dev nic-maas | grep -w inet
     inet 10.31.200.2/24 brd 10.31.200.255 scope global nic-maas

 $ grep $(hostname) /var/snap/maas/current/bind/zone.200.31.10.in-addr.arpa
 2 30 IN PTR maas-srv-31snap.maas.

 $ host maas-srv-31snap.maas 10.31.200.2 | grep 'has address'
 maas-srv-31snap.maas has address 10.31.200.2

 $ sudo ip addr add 10.31.200.10/24 dev nic-maas

 $ ip addr list dev nic-maas | grep -w inet
     inet 10.31.200.2/24 brd 10.31.200.255 scope global nic-maas
     inet 10.31.200.10/24 scope global secondary nic-maas

 (wait a bit)

 $ grep "Reloaded DNS configuration; ip .* connected to $(hostname)" /var/snap/maas/common/log/regiond.log
 2024-02-21 21:34:05 maasserver.region_controller: [info] Reloaded DNS configuration; ip 10.31.200.10 connected to maas-srv-31snap on nic-maas

 Note the change here:

 $ grep $(hostname) /var/snap/maas/current/bind/zone.200.31.10.in-addr.arpa
 10 30 IN PTR maas-srv-31snap.maas.
 2 30 IN PTR nic-maas.maas-srv-31snap.maas.

 $ host maas-srv-31snap.maas 10.31.200.2 | grep 'has address'
 maas-srv-31snap.maas has address 10.31.200.10

 $ sudo ip addr del 10.31.200.10/24 dev nic-maas

MAAS 3.1.3:

 $ sudo snap refresh --channel=3.1/edge maas

 $ ip addr list dev nic-maas | grep -w inet
     inet 10.31.200.2/24 brd 10.31.200.255 scope global nic-maas

 $ grep $(hostname) /var/snap/maas/current/bind/zone.200.31.10.in-addr.arpa
 2 30 IN PTR maas-srv-31snap.maas.

 $ host maas-srv-31snap.maas 10.31.200.2 | grep 'has address'
 maas-srv-31snap.maas has address 10.31.200.2

 $ sudo ip addr add 10.31.200.10/24 dev nic-maas

 $ ip addr list dev nic-maas | grep -w inet
     inet 10.31.200.2/24 brd 10.31.200.255 scope global nic-maas
     inet 10.31.200.10/24 scope global secondary nic-maas

 (wait a bit)

 $ grep "Reloaded DNS configuration; ip .* connected to $(hostname)" /var/snap/maas/common/log/regiond.log
 2024-02-21 21:34:05 maasserver.region_controller: [info] Reloaded DNS configuration; ip 10.31.200.10 connected to maas-srv-31snap on nic-maas
 2024-02-21 21:38:29 maasserver.region_controller: [info] Reloaded DNS configuration; ip 10.31.200.10 connected to maas-srv-31snap on nic-maas

 Note the change here, but this time the IP for first line (2) didn't change:

 $ grep $(hostname) /var/snap/maas/current/bind/zone.200.31.10.in-addr.arpa
 2 30 IN PTR maas-srv-31snap.maas.
 10 30 IN PTR nic-maas.maas-srv-31snap.maas.

 $ host maas-srv-31snap.maas 10.31.200.2 | grep 'has address'
 maas-srv-31snap.maas has address 10.31.200.2